<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div id="app">
    <div :class="a">111</div>
    <!-- 绑定数组 -->
    <div :class="[a, 'box2', 1==1?'box3':'']">222</div>
    <!-- 绑定对象 -->
    <div :class="{a:1===1, b:isTrue, active: true}">333</div>
    <!-- 数组嵌套对象 -->
    <div :class="[a, 'box2', 1==1?'box3':'', {a:1===1, b:isTrue, active: true}]">444</div>
  </div>
  <script src="./vue.global.js"></script>
  <script>
    const { createApp } = Vue;
    const app = createApp({
      data(){
        return {
          a: 'box',
          isTrue: false
        }
      }
    })
    app.mount('#app')
  </script>
</body>
</html>